A Beautiful Cloudiness

 

Our server deposits a flight of beers on our table: a bespoke wooden tray holding a number of small glasses filled with varying degrees of amber. I lean forwards in my seat, ever hopeful, lifting the first glass to my nose. I take a long sniff, followed by a couple of sips. Then I sigh; place the glass back in the tray and slump back in my seat. ‘I’d rather be drinking a Kernel IPA,’ I say and not for the first time on this trip.

Craving a Kernel IPA on the West Coast

Last Autumn we spent three weeks touring US breweries and tap rooms, sampling hundreds of beers. We began with a few days on the east coast but the remainder was spent on the west coast, travelling north from LA to Seattle. Surprisingly, we weren't blown away by the majority of the beers we were drinking (NB in this post ‘beer’ refers specifically to IPA or pale ale unless otherwise stated). It began to dawn on me that I’d been seeking something from these hop-forward beers that I wasn’t getting and it was leaving me feeling dissatisfied.

Most of the beers were so bright as to be completely transparent: you could literally read newsprint through them. They were sufficiently bitter but they were lacking in the kind of hop flavours we wanted - they weren’t flavourful or fruity enough. Although sometimes the fruitiness present would be an estery apple flavour - I'd guess from using an English ale yeast. Chris and I had some argument about this at one particular brewery tap where he was convinced it was ethyl acetate he could smell in all of the beers, an unpleasant background flavour which increased as the ABV of the beers rose (he thought the brewery had a wild yeast infection). I wasn't convinced - I was trying to give them the benefit of the doubt, assuming that they just really wanted all of their crystal-laden pale beers to also taste like apple juice. To this day we don't agree on the cause but whether it was intentional or accidental, we did not enjoy it. Just give us a Kernel IPA already.

Super crushy pale ales

There were some exceptions of course. Other Half, Cellarmaker, and Boneyard gave us exactly what we were looking for (you might say they’re the closest thing to a Kernel IPA we came across on this trip). Also Russian River: Blind Pig and Pliny the Elder are both truly amazing hop-forward beers which demonstrate that you can design and execute highly drinkable beers that pair malts (including crystal malts) appropriately with huge in-your-face hop character. But not every West Coast IPA is a Blind Pig. I tasted plenty of bright (filtered) crystal malt-heavy IPAs where the hop flavour seemed muted to my palate.  

In the interests of fairness, there are also breweries making beers which are great but don’t really give me what I’m looking for, e.g. Firestone Walker. Their hop-forward beers are faultless and there absolutely will be times when I want to swig a Union Jack or Easy Jack straight from the can, but I cannot imagine craving them the way I often crave a (hazy) 'hop juice' flavoured IPA. That’s just a personal preference.

It began to seem that more often than not, where haze was absent so was the flavour that I was looking for in an IPA. Is there a connection between the level of haze and the hop flavour in a beer? Is there something missing from these filtered, totally clear beers? Is it yeast? Does filtering out all of the yeast also filter out some of the flavour? If hop flavour compounds bind to yeast in the beer and then get centrifuged and/or filtered out, are we losing some of that hop flavour along with the haze?

So my rough hypothesis was: ‘haze = hop flavour’. I don’t necessarily see it as an exponential relationship, i.e. ‘>haze = >hop flavour’, but there is definitely a positive association between the two factors in my experience. This haze hypothesis was sat at the back of my mind when we returned home from the US. A couple of other issues eventually brought it to the forefront.

The first is our experience of drinking Brewdog beers over the past year or so. We’ve drunk quite a lot of Dead Pony Club and Jackhammer in our time and I know we’re not the first people to say that there have been some consistency issues with their pale beers. Although Punk is probably the most (in)famous for this complaint I’ve had it nowhere near as often as the other two beers so I can’t comment on it. When it’s good, Jackhammer is really good but too often recently we’ve found it washed out flavour-wise. (I was really looking forward to trying Monk Hammer when it launched earlier this year but it had nowhere near the yeast character I was expecting. It just tasted overly bitter.) What was happening to the hop flavour in these beers? We ruled out freshness being an issue affecting flavour since we’re mostly talking about our experience of drinking them in Brewdog bars. Was the flavour being filtered out somehow? 

Top: Born to Die, Bottom: Jackhammer

I think it is only fair to say that while I always think of Brewdog as producing possibly the brightest hop-forward beers in the UK we tried Jackhammer again recently (as described in my last blog post) and it surprised us by being a tiny bit hazy (it was tasting pretty good on that occasion too). In fact, there were two other UK IPAs we had that night which had less haze than a Brewdog beer! That was definitely a shock result. But in general these Brewdog beers still broadly fit within my haze hypothesis – they have very little haze, and they have less of a ‘hop juice' flavour than other (hazier) UK beers. 

By hop juice I mean the experience you get from an IPA which is akin to the thirst-and flavour-quenching feeling you get from drinking some fresh fruit juice. It's not only quenching your thirst - a glass of water could do that, this is more satisfying than water, and it's not just that it tastes like fruit, it's the intensity and the richness of that mouth-watering fruit flavour.

The second issue, the Yeast Coast IPA phenomenon, has highlighted the distinctly different views we have on clarity and haze in beer here in the UK compared to the US. I’ll come back to this later on.

What is haze? 

I wanted to get a better understanding of this subject and to investigate my haze theory. I’m a scientist by profession and I'm happiest when I'm getting into the technical detail of things. So what is it that makes a beer appear hazy anyway?

A visible haze in beer is caused by particles in suspension. The causes of haze can be broadly divided into two groups: biological and non-biological. The former refers to microorganisms, i.e. yeast and bacteria, while the latter refers to everything else (both natural and synthetic compounds). 

Biological haze is the simplest of the two, both to explain and for brewers to remedy. If we’re talking about a clean fermented IPA here (which we are) then we don’t expect bacteria to play a role in that beer. If one or more species of bacteria is present at a level where it makes the beer appear turbid (i.e. cloudy or opaque), then that beer has bigger problems than the way it looks. By the time you can see bacterial growth as turbidity the aroma and flavour compounds it produces will be evident and the beer will be unpleasant to drink.

Yeast

Cloudy beer doesn't always taste great

We can’t make beer without yeast, yet it is not always desirable in the finished beer. If we’re talking about cask, bottle (and keg) conditioned beer then I guess we might expect there to be some yeast in the finished product since it has been used to carbonate the beer in the vessel it’s being dispensed from. The presence of yeast will also have a protective effect on these beers – a residual yeast component will help to reduce oxidative damage to the beer by scavenging free oxygen which may have gotten into the beer during packaging. However, consumers tend to find a bright beer more aesthetically pleasing than a hazy one so most brewers try to produce a beer which has minimal yeast present. Since yeast in beer exists as particles in suspension it will eventually drop out of suspension and fall to the bottom of the vessel all by itself - but that will take some time to occur. The smaller the particle size, the longer they will take the settle out under natural gravitational forces. 

The addition of finings (isinglass) to beer causes the yeast to clump together (an increase in particle size) until they are heavy enough to drop to the bottom. Fining is a way of getting beer into a drinkable condition as soon as possible. For some brewers this is essential because they do not want any yeast in their finished beers. However, some brewers choose not to add anything to their beers to drop them bright. Their beers are served naturally hazy because they feel that by artificially removing the yeast they are also removing flavour from their beer. You can read Moor here.

Hops

Moving on to non-biological haze, what about the presence of actual hop material in finished beers? When people talk about there being a ‘hop haze’ in their IPA - are they talking about their beer being so hoppy that the brewer hasn’t managed to keep all of the hops out of the packaged beer? Well, no, not really. But I’ll share a couple of exceptions with you just to demonstrate that it is possible. In late 2015 I ordered a Pale Fire by Pressure Drop in a north London pub and when it arrived it was on the cloudy side of hazy. In fact it was opaque (back then this beer had a reputation for being hazy, but it was also notorious for being a great pale ale). Because I’d been drinking it all afternoon and it was tasting great I wasn’t put off by the cloudiness. In a short space of time a green sludgy sediment settled out in the bottom of my glass. I daresay if I’d returned it to the bar and said that I didn’t fancy drinking the end of the keg they would have exchanged it for me, no question. But I didn’t ask because I wasn’t bothered by it. More recently we drank a bottle of Kernel IPA Simcoe (as mentioned in my previous post) which had a little bit of hop matter in the bottom which settled out in the glass over time. It was a little reminiscent of drinking homebrew – and we’ve sampled plenty of homebrew that was better than commercial beer so that’s not an insult.

Proteins

Protein-polyphenol interaction model  (Siebert et al, 1996)

The biggest cause of haze in hop-forward beers is usually the formation of complexes of proteins and polyphenols. When we mash grains to brew a beer we generally tend to think of the sugars we obtain from the mash but we also extract proteins of varying sizes. Whilst some of those proteins (e.g. those involved in head retention) are useful, the others are less desirable. Larger proteins are mostly removed by the process of boiling (the hot break) and chilling (the cold break) but some are too small to drop out of suspension. While these proteins remain in solution they are not an issue in haze formation. But they problem is that they do not stay in solution forever.

Maybe you’ve heard of chill haze? This is a temporary effect where temperature sensitive reactions cause proteins to aggregate, as the beer is chilled close to freezing. These reactions cause the formation of reversible bonds (that’s non-covalent bonds for the scientists reading this) whereby soluble compounds become temporarily insoluble. These insoluble proteins are visible to the naked eye. As the beer warms up these reactions are reversed, the insoluble becomes soluble again and the haze disappears. But as the beer ages this chill haze will eventually become a permanent haze (caused by irreversible covalent bonding) which does not dissipate even at room temperature.

The issue is that it is difficult to remove all of this unwanted protein. Beers which undergo late hopping and dry hopping will have high levels of polyphenols present. The formation of protein-polyphenol compounds is inevitable over time and it will increase with age.

Reducing haze

The greater the level of hop additions in a beer, the hazier it will become over time. Haze is a tricky problem because it won't actually just go away on its own. Quite the opposite - it will make itself more evident with time, not less. Yeast can be removed with relative ease. Plenty of professional brewers are keen to tell you how easy it is to make a bright beer, provided you allow enough time and you control the temperature. Actually, yet another stimulus I had for writing this post was seeing some brewers boasting on social media about the clarity of their beer, with the inference (sometimes implicit, sometimes explicit) that brewers who can't (or choose not to) get their beer just as bright are inferior.

But protein is a lot harder to get out of your beer than yeast. Much of the problem is that it's not all in suspension. Some of it is in solution. Unless you can get it to come out of solution you can't get it out. What you can do is remove as much as possible of the protein which is in suspension by centrifugation. This will produce a haze free beer at the point of packaging. But the protein in solution will not be removed and at some point in the future it will come out of solution and bind to polyphenols in the beer, then it will become visible as haze.

Filtration is the next step up from centrifugation. It's not as simple as filtered or unfiltered. Beer can be filtered to varying degrees (e.g. 20μm or 0.5μm) depending on the specific desires of the brewery. There are a number of different methods and materials which can be used for filtration - it's a complex topic but as much as it fascinates me I'm not going into more detail here. I might well return to it in a future post though.

Hazy, Cloudy, or Murky?

L-R: Kernel Simcoe IPA, Jackhammer, Halcyon, Cloudwater DIPA V3

In the UK we are seeing a spectrum of haze levels in beer. At one end we have the transparent beers from Brewdog, where recently it seems as if a lot of the hop aroma and flavour has been removed along with all the particulate matter (yeast, hop matter and protein). In terms of body they can compare unfavourably to beers with more haze but at least their beers are appropriately carbonated and this does help to aid the mouthfeel and body. At the other end we have breweries like The Kernel whose beers are never truly bright, but which generally smell and taste of all things I want from hop forward beers. 

And since it’s a spectrum we have breweries who fall somewhere in between these two extremes. For example, Magic Rock produce beers which are not truly bright but (with the exception of their seasonal double and triple IPA) are not actually that hazy*. I can report from extensive sampling that their pale beers have a decidedly in-your-face hop character. The flavour is not being stripped out of Cannonball or High Wire. I would always choose aroma and flavour over clarity, but it's not my choice to make. That is a decision for each brewery to make and it will be based on many factors – not just how beer nerds feel about it.

Delicious haze

Leaning further still toward The Bright Side are Thornbridge. In fact, many times whilst pondering this subject I wondered if they were the missing piece in this puzzle – juggling the fine balance between clarity and hop flavour. For example, Halcyon is a very bright beer but I know it still carries a floral/citrusy hop smack in the face when it’s fresh. They show it is possible to centrifuge most of the particulate matter out of your hop-forward beers and still retain a striking hop character.

In the UK we have some 'baggage' associated with clarity and 'clear beer', which stems from the bad old days when a hazy beer could have been an indicator of poorly kept cask beer. Those days are gone now. Well, they are for most people but some beer drinkers still act as if the situation hasn't changed since the 1970's and that a hazy pint must be sent back because it will make them sick. There's a nice Boak and Bailey post on the subject here.

In the US though they never had the problem of poorly kept cask beer to worry about, so hazy beer doesn't have the same automatic negative associations as it does in this country. So it's only natural that they feel differently about it there.  

 

The New Hazy: The New England IPA

Fruit juice or hop juice?

Please click here to see the incredible Yeast Coast IPA gallery.

If you’re interested in IPA (and you probably wouldn’t have read this far if you aren’t) then you’ll have probably seen or heard some discussion on the concept of West Coast vs East Coast IPA. I think this piece is probably my favourite. It came across my feed on April Fool’s Day this year so at first I wasn’t sure if it was for real or not. I might still not be 100% convinced.

When I think of a West Coast IPA I think of Blind Pig or Pliny the Elder from Russian River – they’re resinous, dank, and seriously bitter beers but that fierce bitterness is balanced out by sweetness from the malts. When they’re fresh the sweet and bitter exist together in perfect harmony and it’s glorious. When I think of an East Coast IPA, up until our most recent visit to NY and New England (in 2015), I was thinking of an essentially less bitter, more muted version of the West Coast IPA. I’d had The Alchemist's Heady Topper and Focal Banger, some Other Half stuff, some Trillium, a bunch of Hill Farmstead, and other than being a little bit hazier and less bitter than the West Coast stuff – I wasn’t really seeing any major differences.

I’ve done extended beer drinking on the West Coast and (even though it’s further away) we see plenty of that type of US beer imported to the UK, but with the East Coast stuff you just don’t see it over here. None of those breweries I mentioned are imported to the UK. The only way you’ll have tried them is either by going there yourself or if you’re lucky enough to have a friend bring you some back. I guess because I’ve only really sampled these beers on sporadic occasions I’d not been able to put the pieces together into a bigger picture until more recently. 

Anyway I’m not going to totally derail this entire post into an East Coast vs West Coast IPA debate, but let’s just say, if you thought that London Murky was bad then you’re going to love this.

A number of New England breweries (e.g. Treehouse, Trillium, Tired Hands) are producing these 'hop juice' style IPAs which are incredibly hazy to look at. Some people have assumed that this is caused solely by yeast left in solution, but it’s more complicated than that. There is generally a particular yeast  involved: the ‘Conan’ strain (made famous by Heady Topper) or a variation of it;  that yeast is less flocculent (it does not completely drop out of solution) than strains traditionally used in US pale beers. However, these recipes also give special attention to water profile (i.e. favouring chloride over sulphates to produce a softer mouthfeel and to encourage a hazy appearance), and the use of grains which are known to affect body and mouthfeel (e.g. various types of wheat). Again – this post isn’t really about New England IPA. If you do want to read more about it there’s a very good article here which focuses on the mouthfeel of this style of beer.

The way these beers are viewed by beer geeks in the US is absolutely fascinating to me. Tree House Brewing Co have a beer named Haze. Here are some descriptions of its physical appearance on Beer Advocate where it has a score of 99:

-Incredibly turbid, murky pineapple

-turbid honey orange color

-nice cloudy deep orange

-Pours a very turbid, hazy orange color

-Murky, and yes hazy dark yellow orange. A beautiful glowing orb with some light behind it

These people are definitely not using the terms 'hazy', 'murky' or 'turbid' as negative descriptors of this beer. They are describing its opaque appearance as a positive quality. You simply cannot imagine anyone in the UK using the word ‘turbid’ to describe an IPA in a positive way, can you? I can’t.

 

Some homebrewers are also adding ingredients to their beers to deliberately make them look cloudy. I’ll just say that again: they are making their beers cloudy on purpose because they think they look better that way. For anyone else who finds this topic as fascinating as me, plenty of bedtime reading can be found here.

Here’s brewer and expert yeast wrangler Michael Tonsmiere on adding flour to his IPA to make it soft and juicy. The title of this blog post by the way is a quote from a homebrewer describing their attempt to emulate Tonsmiere’s hop juice NE IPA. I’ve read hundreds of posts on US homebrew forums where people are trying to brew this style of beer, with particular attention to its appearance. As a homebrewers Chris and I have had plenty of weird ideas (and brewed some of them) but I cannot get my head around adding flour to make your beer cloudy because you think it looks better that way. Caring more for aroma and flavour than appearance cuts both ways I suppose.

Drink Fresh vs. Distribute Widely

For the brewers who aren't deliberately trying to produce hazy beer there is a choice to be made: doing nothing about its appearance or refining it. Moor have made an overall decision not to fine or filter their beers but they are not the only UK brewery who choose not to process their beers beyond waiting for the yeast and dry hop to drop out. Deciding to leave beer free of any other processing at that point will affect how that beer ages. The ultimate journey and destination of those beers can impact on the decision to make a more stable, long-lasting product - i.e. by centrifuging and or filtering to remove particulate matter which can affect the quality of the beer in the future.

We were fortunate to get a very detailed tour of the Firestone Walker brewhouse and processing facility while we were in the US last year, so we’re familiar with how they process and package their beers. You might have seen cans of their pale beers in the UK these days - they package their beers with that wide distribution in mind. As with all hop-forward beers, they will be at their absolute pinnacle the moment they go into the can and they will incrementally diminish from that moment forwards. However, because their beers are so clean, refined, and devoid of particulate matter at that moment of packaging their eventual demise will be a gentle lessening of character. The cost of that longevity and stability is that you have to give up some hop character from your hop-forward beers to make them last longer. It's a fine balance.

We also had a nose around the brewhouse at Russian River, where we learned that the beers on tap in the brewpub are processed differently to the ones which are packaged in kegs and bottles for distribution elsewhere in the state. The beer which is brewed to be drunk fresh undergoes less processing because it's not travelling anywhere or undergoing changes in temperature - it's not even leaving the premises, so there's no danger of it getting old. Is this the solution to the drink fresh vs. distribute widely conundrum? 

The most obvious solution to the longevity of your beer, however, is to not bother with wide distribution at all. It's difficult to find Kernel beers outside of London - because they believe in the drink fresh, drink local model of production. 

The Theory of Haze

I've had Pale Fire recently (both keg and bottle) after long period of not drinking it  and the first thing I noticed was how bright it was, like 'is this definitely the right beer?' level of brightness. And guess what? It didn’t taste as good as I remember it tasting when it was a hazier beer. It tasted kind of tame to me...I KNOW, I KNOW. That’s confirmation bias. There’s plenty of reasons why it might taste different now to how it did a year ago and it could be nothing whatsoever to do with the level of haze. 

I have always cared more for aroma and flavour than for appearance when it comes to beer. Haze has never bothered me. I’ve had some delicious cloudy IPAs too – a recent example being Magic Rock’s Human Cannonball. I know the brewery would rather it was a little less hazy (and that this is something they wish to address in the future) but that didn’t prevent lots of us from thoroughly enjoying it.

More often than not, hazy beers have proved to taste better to me than bright beers. I know that correlation doesn’t equal causation but my evidence demonstrates a positive association between the two factors.I do keep hoping that one day a filtered beer will surprise me by tasting as good as or better than an unfiltered one to me. I remain open to that possibility. But in the meantime I’ll keep drinking hazy beers because I like the way they taste. 

Cloudwater DIPA V3 - UK brewed Yeast Coast IPA

*Haze is a subjective term in this post, obviously. Nobody is ever going to agree on precisely what is or isn’t haze.

NB: I contacted a number of professional UK brewers before writing this post. My gratitude goes to Rob from Thornbridge for taking time to discuss this topic with me at length, and also to Stu from Magic Rock and Toby from The Kernel who took time to answer my questions.

On the other side of the pond so many people gave up their time to show us their breweries and taprooms on our trip which we really appreciated. But in relation to this post:  we are grateful to staff at Russian River's brewpub, and especially to Sam Tierney at Firestone Walker for the ultimate brewery tour.